Asphaltene dispersants - inhibitors

ABSTRACT

An asphalt/asphaltene dispersant comprising an admixture of polymer A and polymer B ranging from 100 to 10 weight percent A to from 10 to 100 weight percent B. Wherein polymer A is an alkyl substituted phenol-formaldehyde liquid resin having a weight average molecular weight ranging from about 1000 to about 20,000 and an alkyl substituent containing from 4 to 24 carbon atoms, with alkyl substituent may be linear or branched alkyl group. Polymer B is a hydrophilic-lipophilic vinylic polymer.

INTRODUCTION

Asphalts and asphaltenes are normally occurring constituents in crudeoils These materials have been defined as dark brown to blackcementitious materials in which the predominating constituents arebitumens that occur in nature or which are obtained in the processing ofpetroleum and crude oils. These materials characteristically containvery high molecular weight hydrocarbons sometimes referred to asasphaltenes, and are essentially soluble in carbon disulfide, areprimarily aromatic in nature, but may also be identified as containingvarying amounts of sulfur, oxygen, and nitrogen.

These asphalt and asphaltene components cause varying degrees ofdifficulties in various processes which are aimed at recovering crudepetroleum oils and preparing them for either transportation throughpipelines, or in the refining, separation, or other processes requiredto recover valuable products from crude petroleum oil. In fact, theseasphalt and asphaltene components often cause difficulty byprecipitating or fouling pumps installed underground for the purpose ofrecovering these crude oils.

The presence of asphalts and asphaltenes in crude oil and in otherfractions of petroleum cause difficulties in the recovery,transportation, and treatment and refining of these crude oils and thevarious fractions of crude oils in which these asphalts and asphaltenesare contained. As a result, it would be an advance in the art if anasphalt/asphaltene dispersant could be used initially in the recovery ofcrude oil, and then later in the transportation and refining ortreatment of crude oil or crude oil fractions which contain theseasphalts and/or asphaltenes. Such asphaltene dispersants are known, butare based on chemically formulated alkyl succinates or on chemicallyformulated cresylic acids, and modified products containing thesematerials.

OBJECTS

It is therefore an object of this invention to describe a method ofdispersing and maintaining in dispersion certain asphalts and/orasphaltenes in crude oil or crude oil fractions in a way to inhibit orprohibit the precipitation and formation of deposits due to the presenceof these asphalts and/or asphaltene components.

It is a further object of this invention to identify a series ofpolymers which act as asphalt and asphaltene dispersants in crude oiland other hydrocarbon fractions of crude oil.

It is also an object of this invention to identify compositions ofcertain alkyl substituted phenol-formaldehyde resins which can act asdispersants for asphalts and asphaltenes in crude oil and crude oilfractions containing these asphalts and asphaltenes.

It is also an object of this invention to identify certainhydrophilic-lipophilic vinylic polymers which also act as asphalt andasphaltene dispersants in crude oil and crude oil fractions.

Finally, it is an object of this invention to teach a combination ofpolymeric products, which combination include alkyl-substitutedphenol-formaldehyde resins and hydrophilic-lipophilic vinylic polymersfor use as asphalt/asphaltene dispersants and anti-foulants when addedin effective amounts to crude oil, petroleum oil, or fractions thereof,in the recovery, transportation, or treatment and refining of thesecrude petroleum oils and petroleum fractions.

THE INVENTION

We have discovered a method of dispersing and maintaining fluidity ofasphalt/asphaltenes fractions in hydrocarbons chosen from the groupconsisting of petroleum oils, crude oils, and hydrocarbon fractionsthereof; which hydrocarbons contain these asphalt and asphaltenes, whichmethod comprises treating the asphalt/asphaltene containing hydrocarbonswith an effective asphalt/asphaltene dispersing amount of a liquidpolymer chosen from the group consisting of alkyl phenol-formaldehyderesins having a weight-average molecular weight ranging between about1,000-20,000.

The liquid alkyl phenol-formaldehyde resins are primarily those resinswhich contain alkyl substituted phenols where the alkyl substituent canrange from C₄ -C₁₆ and is chosen from linear and branched alkyl groups.

An asphalt/asphaltene dispersant comprising an admixture of polymer Aand polymer B ranging from 100 to 10 weight percent A to from 10 to 100weight percent B, wherein polymer A is an alkyl substitutedphenol-formaldehyde liquid resin having a weight average molecularweight ranging from about 1000 to about 20,000 and an alkyl substituentcontaining from 4 to 24 carbon atoms, with alkyl substituent may belinear or branched alkyl group; and polymer B is ahydrophilic-lipophilic vinylic polymer having a structure essentiallydescribed as: ##STR1## wherein

R is chosen, at each occurrence, from hydrogen and methyl groups; and

R' is a hydrocarbonaceous group containing from 4-24 carbon atoms andchosen from linear or branched alkyl groups, aromatic, cyclic, alkaryl,aralkyl groups, and mixtures thereof; and

Q is chosen from the groups, ##STR2## and mixtures thereof; and M ischosen, at each occurrence, from the group hydrogen, alkali metalcations, alkaline earth metal cations, ammonium ions, protonated amines,quaternary amines, hydroxyl ethyl, hydroxy propyl and ##STR3## groups,and mixtures thereof; and R" is chosen, at each occurrence, from thegroup ##STR4## and mixtures thereof; and

m and n are both integers of sufficient number to achieve a weightaverage molecular weight ranging from about 5,000-250,000, and being ofsuch a ratio as to describe the presence of from 90 to 10 weight percentof the lipophilic monomer, m, and from 10 to 90 weight percent of thehydrophilic monomer, n, and

wherein

x ranges from 1 to 20.

Preferably, the substituted phenol-formaldehyde resins are those resinswhich are derived from C₆ -C₁₂ alkyl substituents, which substituentsmay be linear or branched alkyl substituents and which are attached to aphenol-formaldehyde resin at either the para or ortho positions (orboth) of the phenolic ring making up the phenol portion of said resin.Preferably, the weight average molecular weight of these liquid resinsranges between about 2,000 to about 15,000 and most preferably themolecular weight ranges between about 2,500 to about 12,000. Theseresins may be linear, branched, or even cross-linked, but when branchedor cross-linked, the resins must have only sufficient branching orcross-linking so as to remain liquid at temperatures from 0° C.-500° C.,or at least able to be suspended stably in inert hydrocarbon solvents.

The most preferred alkyl substituted phenol-formaldehyde resin is aliquid resin derived from an acid catalyzed or base catalyzed reactionof from 1:1.5 to 1.5:1 mole ratio of nonyl phenol and formaldehyde,which liquid resin has a weight average molecular weight ranging betweenabout 2,000 to about 8,000.

The treatment of crude oil or crude petroleum oil, or any hydrocarbonfraction thereof, either during the recovery, transportation, orprocessing and refining of same, with an effective amount of the aboveidentified alkyl substituted phenol-formaldehyde resins, is to maintainin dispersion in the treated oil phases these asphalt and asphaltenesand prohibit and/or inhibit fouling, precipitation, or the build-up ofasphaltic deposits in equipment that is designed for storing, handling,pumping, transporting, or refining these crude oils, petroleum oils, orfractions thereof. This treatment may be achieved at temperatures as lowas -10° C. up to temperatures exceeding 500° C., but the usualtemperature of treatment is from about 1° C. to 400° C.

As stated earlier, the effective dispersing amounts of these liquidalkyl phenol-formaldehyde resins are those amounts that range betweenabout 1 to about 10,000 ppm of the liquid resin relative to the crudeoil, petroleum, or crude oil fraction that is being treated therewith.The preferred range ranges between about 2.5 to about 1,000 ppm, and themost preferred concentrations range between about 5 ppm to about 500 ppmagain based on the resin treating the crude oil, petroleum, or petroleumfraction containing the asphalts and/or asphaltenes.

The alkyl phenol is most preferably a C₈ -C₁₂ alkyl phenol where thealkyl substituent on the phenol ring may be linear or branched, and ismost preferably nonyl phenol which is condensed with formaldehyde atapproximately a 1:1 mole ratio using either acid or base catalysis, soas to achieve a condensed nonyl phenol-formaldehyde resin which isliquid and has a molecular weight ranging between about 1,000 to about20,000, preferably between about 2,000 to about 12,000, and mostpreferably having a molecular weight of about 2,000-5,000.

However, we have also discussed other polymers which may also be used tosuccessfully disperse asphalts and asphaltenes in hydrocarbon liquidmedia, as above, and maintain fluidity of these asphalts and asphaltenesin the hydrocarbons which contain the same. These other polymers arepolymers which can be described as hydrophilic-lipophilic vinylicpolymers (henceforth H-L V Ps). These H-L V Ps have a weight averagemolecular weight ranging between about 5,000 to about 250,000, andcontain mer units which are repeating and randomly distributed on thepolymer backbone, which mer units are derived from the hydrophilicmonomers and lipophilic monomers described below.

The lipophilic monomers are primarily those monomers chosen from thegroup consisting of acrylate or methacrylate fatty esters, i.e. whereacrylic or methacrylic acid has been esterified using a fatty alcoholchosen from an alcohol containing from C₄ -C₂₄ carbon groups, therebyleading to an acrylate or methacrylate ester where the esterfunctionality contains hydrocarbonaceous substituents including linearand branched alkyl substituents, aromatic, cyclic, alkaryl, aralkylsubstituents or mixtures thereof; and where the hydrocarbonaceous groupscontain from 4-24 carbon atoms.

Preferably these fatty ester acrylates or methacrylates are those esterswhich are derived from alcohols containing from 8-16 carbon atoms, andpreferably are those alcohols, such as lauryl alcohol and the like. Themost preferred lipophilic monomer used to form thehydrophilic-lipophilic vinyl polymers is lauryl acrylate.

These lipophilic monomers are polymerised with a vinylic hydrophilicmonomer, which hydrophilic monomer is chosen from acrylic acid ormethacrylic acid, and their organic or organic salts, and the non-fattyacrylate or methacrylate esters, where the ester functionality containsa polar unit, such as an alcohol, amine, carboxylic acid, amide,quaternary nitrogen salt, and the like. These hydrophilic vinylicmonomers are primarily those monomers chosen from acrylic acid,methacrylic acid, acrylamide, methacrylamide, hydroxyethylacrylate,hydroxypropylacrylate, and the like. The most preferred hydrophilicmonomer is hydroxyethylmethacrylate.

This hydrophilic-lipophilic vinyl polymer contains from about 90 weightpercent to about 10 weight percent of the lipophilic monomer and about90 weight percent to about 10 weight percent of the hydrophilic monomer.Preferably, these H-L V Ps contain about 70 weight percent of thelipophilic monomer and 30 weight percent of the hydrophilic monomer.However, these polymers may also contain any ratio of lipophilic monomerto hydrophilic monomer which ranges between about 10:1 to about 1:10.

These H-L V Ps are copolymers which can contain at least one or more ofboth of the above described hydrophilic and lipophilic monomer units,and are those polymers which can have molecular weights ranging fromabout 5,000 up to about 250,000, preferably between about 10,000 up toabout 150,000, and most preferably are those polymers which have aweight average molecular weight ranging between about 20,000-100,000.The most preferred hydrophilic-lipophilic vinylic polymer which may beused by itself, or in combination with the alkyl phenol-formaldehyderesins described above, are H-L V Ps derived from lauryl acrylate andhydroxyethylmethacrylate, which polymers contain from about 90 to about30 weight percent lauryl acrylate and from about 10 to about 70 weightpercent hydroxyethylmethacrylate. These laurylacrylate/hydroxyethylmethacrylate H-L V Ps have a molecular weightnormally ranging between about 10,000-150,000, and preferably betweenabout 20,000-100,000, and most preferably between about 40,000-80,000.In all cases, where molecular weight is referred to in this application,it is referred to in terms of weight average molecular weight.

COMBINATIONS OF POLYMERS

The alkyl phenol-formaldehyde resins and the H-L V Ps described aboveand later, may be used either alone in treating hydrocarbons whichcontains asphalts or asphaltenes, or preferably they are used incombination, one with the other. The combination can include from 100percent alkyl phenol-formaldehyde liquid resin and zero percenthydrophilic-lipophilic vinylic polymer to zero percent alkylphenol-formaldehyde liquid resin and 100 percent hydrophilic-lipophilicvinylic polymer.

However, it is preferred that the alkyl phenol-formaldehyde liquidresins described above are present between about 10 to about 90 weightpercent and the H-L V Ps are present from about 90 to about 10 weightpercent in a formulation to be used to treat crude oils, petroleum oils,or hydrocarbon fractions thereof, which contain asphalts andasphaltenes.

It is particularly useful to use as the asphaltene dispersant of thisinvention, an asphalt/asphaltene dispersant which comprises from 20 to100 weight percent of an alkyl substituted phenol-formaldehyde liquidresin having about a 1:1 mole ratio of alkyl phenol to formaldehyde anda molecular weight ranging between about 1,000 to about 20,000, andwherein the alkyl substituent is a linear or branched alkyl groupcontaining from five to twelve carbon atoms; and from 80 to 0 weightpercent of a hydrophilic-lipophilic vinylic polymer having a molecularweight between 5,000-250,000, and containing from 90 to 10 weightpercent of a fatty (meth)acrylate ester and from 10 to 90 weight percentof a hydrophilic monomer chosen from the group consisting of (meth)acrylic acid, (meth) acrylic-acid salts, and (meth) acrylic acidalkoxylate esters.

By the term "fatty (meth)acrylate" we mean either an acrylic acid or amethacrylic acid ester derived from a fatty alcohol containing from four(4) to twenty-four (24) carbon atoms, and preferably from 8-16 carbonatoms and being either linear or branched alkyl alcohols. In general,the term (meth)acrylic(ate) refers to either or both of acrylic acid, ortheir salts, esters, or the like. (Meth)acrylic acid salts can includealkali metal salts, alkaline earth metal salts, ammonium salts, or saltsderived from protonated amines (primary, secondary, or tertiary amines)or from quaternary amines.

The ester of (meth)acrylic acid can also include alkoxylate esters suchas hydroxyethyl (meth)acrylate. The alkoxylate esters are primarilyhydrophilic monomers while the alkyl esters are primarily lipophilicmonomers, particularly when the alcohol used to esterify the(meth)acrylic acid has at least four carbon atoms.

Preferably the effective method for treating crude oils, petroleum oils,and petroleum or hydrocarbon fractions which contain asphalts andasphaltenes is a method which permits the treatment of these hydrocarbonmaterials with from about 1.0 up to about 10,000 ppm, based on thehydrocarbon material treated, of any of the asphaltene dispersantformulations of this invention, but the preferred method uses adispersant formula which contains from 60-95 weight percent of a nonylphenol-formaldehyde liquid resin, having a molecular weight betweenabout 1,000 to about 12,000, and which dispersant formulation alsocontains about 40 to about 5 weight percent of a hydrophilic-lipophilicvinylic polymer, which hydrophilic-lipophilic polymer contains from80-20 weight percent lauryl acrylate and from about 20-80 weight percenthydroxyethylmethacrylate. As before, the preferred molecular weight ofthis hydrophilic-lipophilic vinylic polymer ranges between about20,000-100,000, and most preferred molecular weight ranges between about40,000-80,000.

To exemplify the use of our asphalt/asphaltene anti-precipitants,anti-foulants, and/or dispersants, the following examples are presented.

EXAMPLES

The test procedure for evaluating asphaltene dispersants was developedas follows:

1) 10 ml of hexane is added to a graduated centrifuge tube. To this tubeis added the test dispersant. The test dispersant may be added in adiluted form, but is preferably present at dosages (on an active basis)ranging between 1 to about 100 ppm.

2) To the mixture now contained in the centrifuge tube, 100 μl of anasphaltene stock is added. The stock is formed by dissolving 10 percent,by weight, of either an asphaltic precipitate obtained from a refineryor a precipitated asphaltic residue obtained by treating an asphalticcrude oil (such as an oil obtained from Wyoming) with hexane at a volumeratio of from about 4:1 to about 30:1 hexane:crude, into a heavyaromatic naphtha solvent having a boiling point above 200° C.

3) The centrifuge tubes are then capped and shaken vigorously for abouttwenty-thirty seconds, or shaken by hand at least fifty times. Thecentrifuge tubes are set aside and the contents allowed to settle. Thevolume percent of precipitate is recorded as a function of time, and ata given time, a percent retention value is calculated.

4) When settling of the residue is complete, 1 ml of the top layeredsupernate is collected, diluted with 3 ml of the same heavy aromaticnaphtha used to make up the standard solutions, and the optical densityor absorbance of this sample as measured at 475 nanometers by amini-spec 20 photometer is obtained.

5) Performance is indicated by two parameters: One parameter is thepercent retention of asphalt/asphaltenes in the upper phase in a giventime, as measured by the volume ratio of asphaltenes to solvent layers;and the other parameter is the percent dispersion as measured by theoptical density or absorbance from the upper supernate liquid layer.

6) The percent retention expresses the difference in asphalteneprecipitation volume between a sample and the blank, as a percent of theprecipitation volume of the blank, i.e., the percent retention equalsthe precipitate volume of the blank minus the precipitate volume of thetreated sample, divided by the precipitate volume of the blank.

7) The percent dispersion value is calculated as the optical density ofthe sample minus the optical density of the blank divided by the opticaldensity of the reference minus the optical density of the blank, timesone hundred.

Using these test procedures and calculations, the data in Tables I, II,III, and IV, present the results obtained when using the alkylphenol-formaldehyde resins of this invention. These resins are comparedto commercial products which are either derived from alkenyl maleicanhydride products, which products are then esterified and formulated asdispersants for asphalts/asphaltenes, or commercial products which areformulated based on cresylic acid modified materials.

                                      TABLE I                                     __________________________________________________________________________    Asphaltene Dispersant Test Results.sup.a                                                          Dosage                                                                            Volume % Precipitate                                                                      % Retention                               Sample                                                                            Description     (ppm)                                                                             5 min.                                                                            10 min.                                                                           80 min.                                                                           80 min.                                   __________________________________________________________________________    1   Nonyl phenol-formaldehyde resin                                                               10  0.2 0.3 0.6 81                                        2   Commercial product "A"                                                                        10  0.3 0.5 0.8 75                                        1   Nonyl phenol-formaldehyde resin                                                               50  0.2 0.4 0.8 75                                        2   Commercial product "A"                                                                        50  0.3 0.6 1.0 69                                            Blank           --  1.5 2.8 3.2  0                                        __________________________________________________________________________     .sup.a Asphaltenes from a Southern state refinery                        

                                      TABLE II                                    __________________________________________________________________________    Asphaltene Dispersant Test Results.sup.a                                                          Dosage                                                                            Volume % Precipitate                                                                     % Retention                                Sample                                                                            Description     (ppm)                                                                             15 min.                                                                             210 min.                                                                           210 min.                                   __________________________________________________________________________    1   Nonyl phenol-formaldehyde resin                                                                5  0.5   1.1  74                                         2   Commercial product "A"                                                                         5  0.8   0.9  79                                         1   Nonyl phenol-folmaldehyde resin                                                               50  0.5   0.9  79                                         2   Commercial product "A"                                                                        50  0.5   1.1  74                                         3   Aromatic naphtha                                                                              50  1.1   3.0  29                                             Blank           --  3.0   4.2   0                                         __________________________________________________________________________     .sup.a Asphaltenes from a Southern state refinery                        

                                      TABLE III                                   __________________________________________________________________________    Asphaltene Dispersant Test Results.sup.a                                                          Dosage                                                                            Volume % Precipitate                                                                      % Retention.sup.b                                                                    % Dispersion.sup.c                 Sample                                                                            Description     (ppm)                                                                             8 min.                                                                            80 min.                                                                           18 hrs.                                                                           18 hrs.                                                                              18 hrs.                            __________________________________________________________________________    1   Nonyl phenol-formaldehyde resin                                                               5   0.2 0.5 1.5 62     40                                 2   Commercial product "A"                                                                        5   0.2 0.6 1.5 62     38                                 3   Aromatic naphtha                                                                              5   1.8 3.0 3.0 25     17                                 4   Commercial product "B".sup.e                                                                  5   0.3 2.3 3.5 22     24                                 5   Commercial product "C".sup.f                                                                  5   1.0 4.2 4.0  0      8                                     Blank.sup.g     --  3.2 4.2 4.0  0      0                                     Reference.sup.h --  --  --  --  --     100                                __________________________________________________________________________     .sup.a Asphaltenes hexane extracted from Wyoming crude oil                    .sup.b Based on amount of precipitate                                         .sup.c Based on optical density of hexane phase                               .sup.d Alkenylmaleic anydride/esterified based product                        .sup.e Cresylic acid based product                                            .sup.f Cresylic acid based product                                            .sup.g Hexane & asphaltene*                                                   .sup.h Aromatic solvent & asphaltene*                                         *Hexane addition to petroleum fractions tends to precipitate                  asphalts/asphaltenes from these fractions, therefore no retention, or ver     little retention is observed. Normally, aromatic solvents do not have thi     effect and therefore retention is very high, or complete.                

                  TABLE IV                                                        ______________________________________                                        Asphaltene Dispersant Test Results.sup.a                                      Alkyl phenol-Formaldehyde Resin Series                                        Sample                                                                              Phenol-Alkyl Groups                                                                          Resin MW  PPM  % Dispersion                              ______________________________________                                        1     nonyl          2,300     10   36                                        2     nonyl          4,500     10   51                                        3     t-amyl         3,300     10   23                                        4     nonyl/butyl    1,400     10   26                                        5     nonyl/dinonyl  2,000     10   33                                        6     nonyl/dinonyl  3,500     10   40                                        1     nonyl          2,300     40   40                                        2     nonyl          4,500     40   47                                        3     t-amyl         3,300     40   37                                        4     nonyl/butyl    1,400     40   29                                        5     nonyl/dinonyl  2,000     40   37                                        6     nonyl/dinonyl  3,500     40   35                                              blank                    --    0                                        ______________________________________                                         .sup.a Asphaltenes from a refinery in a northern winter state (U.S.)     

                                      TABLE V                                     __________________________________________________________________________    Vinyl Polymers                                                                Laboratory Asphaltene                                                         Test Results     Vinyl Polymer Descriptions                                        Dosage                                                                            Retention                           Molecular                        Polymer                                                                            (ppm)                                                                             (in %)                                                                             Code                                                                             Monomers         Weight %                                                                            Mole %                                                                             Weight                           __________________________________________________________________________     1   5   10   a  Acrylic Acid      5.2   9.0 --                                    50   5   a  Butyl Acrylate   81.7  79.3                                                   Dimethylamino ethyl methacrylate                                                               10.1   8.0                                                   Methyl Methacrylate                                                                             3.0   3.7                                   2   100 89      Butyl acrylate   75.0  75.3 27,000                                            Hydroxyethyl acrylate                                                                          19.8  21.9                                                   Lauryl acrylate   5.2   2.8                                   3   10  79   a  Butyl acrylate   37.3  46.0                                       5   91   a  Hydroxyethyl methacrylate                                                                      23.0  27.9 --                                    50  88   a  Lauryl acrylate  39.7  26.1                                       100 88   a                                                                    100 93   a                                                                4   100 30   a  Butyl acrylate   95.0  95.1 --                                                Hydroxyethyl methacrylate                                                                       5.0   4.9                                   5   100 71   a  Butyl acrylate   84.4  84.5 15,500                                            Dimethylamiro ethyl methacrylate                                                                8.4   7.5                                                   Hydroxyethyl acrylate                                                                           7.2   8.0                                   6   100 30   a  Butyl acrylate   85.2  83.3 --                                                Vinyl pyrpolidone                                                                              14.8  16.7                                   7   10  33   a  Butyl acrylate   24.9  22.3 97,000                                100 62   a  Vinyl pyrpolidone                                                                              75.1  77.7                                   8   100 23   a  Butyl acrylate   79.8  82.0 --                                                Vinyl trimethoxysilane                                                                         20.2  18.0                                   9   1   33   a  Dimethylamino ethyl methacrylate                                                               27.2  34.8 --                                    5   58   a  Hydroxyethyl methacrylate                                                                      23.2  35.8                                       25  74   a  Stearyl methacrylate                                                                           49.6  29.4                                  10   10  84   a  Hydroxyethyl acrylate                                                                          11.2  20.7 --                                    20  82   a  Lauryl acrylate  88.8  79.3                                       10  82   a                                                                    5   91   a                                                                    10  94   a                                                                    100 88   a                                                                    100 90   a                                                                    5   54   a                                                                    50  60   a                                                               11   20  82   a  Hydroxyethyl methacrylate                                                                      11.8  19.9 --                                                Lauryl acrylate  88.2  80.1                                  12   5   67   a  Hydroxyethyl methacrylate                                                                      11.9  20.0 --                                    5   71   a  Lauryl acrylate  88.2  80.1                                       10  84   a                                                                    3   58   a                                                                    30  62   a                                                                    3   95   a                                                                    30  88   a                                                               13   3   93   a  Hydroxyethyl methacrylate                                                                      17.7  28.4 --                                    30  85   a  Lauryl acrylate  82.3  71.6                                  14   3   76   a  Hydroxyethyl methacrylate                                                                      28.4  42.3 --                                    30  76   a  Lauryl acrylate  71.6  57.7                                  15   3   95   a  Hydroxyethyl methacrylate                                                                      39.0  54.2 42,000                                30  85   a  Lauryl acrylate  61.0  45.8                                  16   3   95   a  Hydroxyethyl methacrylate                                                                      49.8  64.7 --                                    30  85   a  Lauryl acrylate  50.2  35.3                                  17   3   98   a  Hydroxyethyl methacrylate                                                                      56.0  70.2 --                                    30  85   a  Lauryl acrylate  44.0  29.8                                  18   2   74   b  Hydroxyethyl methacrylate                                                                      39.0  54.1 40,000                                5   70   b  Lauryl acrylate  61.0  45.9                                       80  56   b                                                                    1   25   c                                                                    5   29   c                                                                    50  39   c                                                                    5   13   d                                                                    50  62   d                                                                    3   50   c                                                                    30  87   d                                                               19   2   82   b  Hydroxyethyl methacrylate                                                                      30.1  44.3                                       20  78   b  Lauryl acrylate  69.9  55.7                                  20   2   78   b  Hydroxyethyl methacrylate                                                                      30.0  44.2                                                   Lauryl acrylate  70.0  55.8                                  21   5   11   a  Lauryl acrylate  70.0  52.0                                       50   0   a  Vinyl pyrpolidone                                                                              30.0  48.0                                  __________________________________________________________________________     CODE EXPLANATION:                                                             .sup.a Asphaltene residue taken from a Southern state (U.S.) refinery          .sup.b Hexane extracted asphaltenes from Wyoming crude oil #1                .sup.c Hexane extracted asphaltenes from Wyoming crude oil #2                 .sup.d Hexane extracted asphaltenes from California crude oil            

                                      TABLE VI                                    __________________________________________________________________________    Liquid Resin - Vinyl Polymer Blends                                                                     Dosage                                                                            Retention                                       Blend                                                                             Description     Weight %                                                                            (ppm)                                                                             (in %)                                                                             Code                                       __________________________________________________________________________    1   Butylphenol-formaldehyde resin                                                                50    5   66   a                                              Polymer # 12                                                              2   Nonylphenol-formaldehyde resin                                                                58    3   78   a                                              Polymer # 12    42    30  76   a                                          3   Nonylphenol-formaldehyde resin                                                                25    2   60   b                                              Polymer # 18    75    5   70   b                                                                    50  66   b                                          4   Nonylphenol-formaldehyde resin                                                                50    2   56   b                                              Polymer # 18    50    5   64   b                                                                    50  64   b                                          5   Nonylphenol-formaldehyde resin                                                                75    2   60   b                                              Polymer # 18    25    5   60   b                                                                    50  62   b                                          6   Nonylphenol-formaldehyde resin                                                                25    1   36   c                                              Polymer # 18    75    5   50   c                                                                    50  46   c                                          7   Nonylphenol-formaldehyde resin                                                                50    1   32   c                                              Polymer # 18    50    5   21   c                                                                    50  29   c                                          8   Nonylphenol-formaldehyde resin                                                                75    1   29   c                                              Polymer # 18    25    5   46   c                                                                    50  32   c                                          9   Nonylphenol-formaldehyde resin                                                                75    2   78   b                                              Polymer # 21    25                                                        __________________________________________________________________________     CODE EXPLANATION:                                                             .sup.a Asphaltene residue taken from a Southern state (U.S.) refinery         .sup.b Hexane extracted asphaltenes from Wyoming crude oil #1                 .sup.c Hexane extracted asphaltenes from Wyoming crude oil #2                 .sup.d Hexane extracted asphaltenes from California crude oil            

The nonyl phenol-formaldehyde resins used in Tables I and II are thoseresins having a molecular weight ranging between about 2,000 and about6,000, and are formed by reacting nonyl phenol and formaldehyde in abouta 1:1 mole ratio with an acid or base catalyst.

The commercial product "A" is a commercial product based uponalkenyl-maleic anhydride adducts which are then esterified with mono orpolyhydric aliphatic alcohols.

In all Tables, the asphaltenes are derived from refinery asphaltenes orcrude oil extractions and are used as indicated in the above testprocedures. In Table III, commercial product "B" and commercial product"C", are both products derived from cresylic acid modified materials.

In Table IV, various alkyl phenol-formaldehyde resins have beensynthesised with various molecular weights and tested asasphalt/asphaltene dispersants. The asphaltenes tested in Table IV comedirectly from a refinery located in a northern winter state of theUnited States.

In addition to the tests listed above, a product was formulated whichcontained 75 weight percent of the preferred nonyl-phenol product and 25weight percent of the preferred hydrophilic-lipophilic vinylic polymer.In this case, the hydrophilic-lipophilic vinylic polymer contained 70weight percent lauryl acrylate and 30 weight percenthydroxyethylmethacrylate.

This 75:25 weight ratio of nonyl phenol-formaldehyde resin and H-L V Pswere dissolved in an inert aromatic naphthinic hydrocarbon solvent sothat the asphaltic dispersant solution contained 25 weight percent totalpolymeric solids. This solution was along with an emulsion breakeradditive was added to the annulus of a crude oil well recovering crudeoils which were fed to a heater treater used to resolve hydrocarbon andaqueous phases therefrom. This operation continued to operate withinspecification indicating that the use of this asphaltic dispersantformula did not interfere with the emulsion breaker formulas being usedsimultaneously.

At another location resolved crude oil from a heater treater was storedin a crude oil stock tank, which had, over a period of time, collectedprecipitated asphalt and asphaltenes in the bottom of this 500 barrel(about 27,500 gallon) tank, so that approximately 8-10 inches at thebottom of the tank contained a hard asphalt/asphaltene deposit which wasno longer suspended in the oil fraction. Ten gallons of the 25% activepolymer formulation dissolved in ten drums of oil were then circulatedthrough the tank which contained the hardened asphaltic and asphalteneresidues. Tank contents were "rolled", through a hot oiling truck at atemperature of about 180° F. for a period of about two to six hours.Visual inspection indicated that all of the asphaltic bottoms andasphaltenes had been removed, dispersed in the treated oil, and thatsuch results were far superior to a typical tank "roll" which was usedto attempt to remove asphaltenes by simply "rolling" the tank with tendrums of untreated oil.

Finally, at another well head, performance was inadequate and erraticprimarily due to periodic recycling of poorly resolved crude oil(demonstrated to contain high concentrations of asphalts/asphaltenes)from the stock tank into the treater. In spite of addingemulsion-breaking chemicals and other commercial solids (sands, clays,muds, etc.) dispersants to the treater at rates ranging between about 5to 6 quarts a day, calculating to about 150 to about 200 ppm activeingredients in the recovered crude oil, operation at this site wasunacceptable.

The standard solids control additive, a commercial product based onnon-ionic ethoxylate polymers and a fatty acid amide, was replaced withten gallons of a 25 percent active polymer solids formulation containingthe 75:25 weight ratio of the preferred nonyl phenol-formaldehyde resinand preferred hydrophilic-lipophilic vinylic polymer described above.About ten gallons of this formulation was fed into the treater on asingle day. Although no noticeable positive change was observed withinabout the first 24-36 hours, the treater interface, which was ragged andhad been clumping, and which contained large concentrations of asphaltsand asphaltenes, shortly thereafter had a smooth texture and theasphalt/asphaltenes had been dispersed in such a way that a smooth,acceptable oil was obtained from the treater for transfer to thepipeline company. This oil was collected, sampled, analysed, andaccepted for transport by the pipeline company. Continuous addition ofthe preferred polymer to the treater at 4-6 quarts per day was thenrequired to maintain normal treater performance.

In addition, visual inspection of the 27,500 gallon storage tankindicated that by treating the treater with the formulation above, andcirculating the contents of the treater through the storage tank attemperatures ranging between about ambient temperatures (35° F.) toabout 130° F., most of the asphaltene precipitate in the stock tanks hadbeen dispersed, and could be sent through the heater treater to recovera hydrocarbon phase which was acceptable for transport by the pipelinecompany.

Again the use of the preferred formulations of these inventions easilydistributed and dispersed hardened asphaltene and asphaltic residuesinto hydrocarbon oils and maintained these asphaltic/asphaltene residuesin dispersion in these oils, so that this dispersed asphaltenehydrocarbon could be easily transported and processed by refining orother processing steps.

Tables V and VI describe the use of various H-L V Ps (Table V) alone forasphalt/asphaltene dispersions and various combinations of the liquidresins (from nonyl phenol-formaldehyde condensates) and H-L V Ps. As canbe seen, the H-L V Ps can be used alone and also in the preferredcombination of liquid resins and H-L V Ps.

Having described our invention we claim:
 1. An asphalt/asphaltenedispersant comprising an admixture of polymer A and polymer B rangingfrom 100 to 10 weight percent A to from 10 to 100 weight percent B,wherein polymer A is an alkyl substituted phenol-formaldehyde liquidresin having a weight average molecular weight ranging from about 1000to about 20,000 and an alkyl substituent containing from 4 to 24 carbonatoms, which alkyl substituent may be a linear or branched alkyl group;and Polymer B is a hydrophilic-lipophilic vinylic polymer having astructure essentially described as: ##STR5## wherein R is chosen, ateach occurrence, from hydrogen and methyl groups; andR' is ahydrocarbonaceous group containing from 4-24 carbon atoms and chosenfrom linear or branched alkyl groups, aromatic, cyclic, alkaryl, aralkylgroups, and mixtures thereof; and Q is chosen from the groups, ##STR6##and mixtures thereof; and M is chosen, at each occurrence, from thegroup hydrogen, alkali metal cations, alkaline earth metal cations,ammonium ions, protonated amines, quaternary amines, hydroxyl ethyl,hydroxy propyl and ##STR7## groups, and mixtures thereof; and R" ischosen, at each occurrence, from the group ##STR8## and mixturesthereof; and m and n are both integers of sufficient number to achieve aweight average molecular weight ranging from about 5000-250,000, andbeing of such a ratio as to describe the presence of from 90 to 10weight percent of the lipophilic monomer, m, and from 10 to 90 weightpercent of the hydrophilic monomer, n, andwherein x ranges from 1 to 20.2. The asphalt/asphaltene dispersant of claim 1 wherein the ratio of A:Bis between about 80:20 to about 20:80.
 3. The asphalt/asphaltenedispersant of claim 2 wherein R' is chosen from linear and branchedalkyl groups containing from 5 to 12 carbon atoms and Q is ##STR9## andx is from 1-10.
 4. The asphalt/asphaltene dispersant of claim 3 whereinthe weight ratio of A:B is from 70:30 to 30:70 and the polymer A is a1:1 mole ratio of nonyl phenol:formaldehyde liquid resin having amolecular weight of from 2000-8000 and polymer B is a copolymer oflauryl acrylate and hydroxyethyl methacrylate containing from 90-10weight percent lauryl acrylate and from 10-90 weight percenthydroxyethylmethacrylate.
 5. The asphalt/asphaltene dispersant of claim4 wherein polymers A and B are dissolved in an inert aromatic naphthasolvent having a boiling point of at least 100° C. at standardatmospheric pressure.
 6. An asphalt/asphaltene dispersant whichcomprises from 20 to 100 weight percent of an alkyl substitutedphenol-formaldehyde liquid resin having about a 1:1 mole ratio of alkylphenol to formaldehyde and a molecular weight ranging between about 1000to about 20,000, and wherein the alkyl substituent is a linear orbranched alkyl group containing from five to twelve carbon atoms; andfrom 80 to 10% weight percent of a hydrophilic-lipophilic vinylicpolymer having a molecular weight between 5,000-250,000, and containingfrom 90 to 10 weight percent of a fatty (meth)acrylate ester and from 10to 90 weight percent of a hydrophilic monomer chosen from the groupconsisting of (meth) acrylic acid, (meth) acrylic-acid salts, and (meth)acrylic acid alkoxylate esters.
 7. The dispersant of claim 6 wherein thealkyl phenol-formaldehyde liquid resin is a nonyl phenol-formaldehydeliquid resin having a molecular weight of from 2,000 to 12,000 and thehydrophilic-lipophilic vinyl polymer is a copolymer having a molecularweight of from 20,000 to 100,000, and contains lauryl (meth)acrylate andhydroxyethyl (meth)acrylate in a weight ratio of from about 90:10 toabout 10:90.
 8. The dispersant of claim 7 wherein thenonyl-phenol-formaldehyde resin and the vinyl polymer containing lauryl(meth)acrylate and hydroxyethyl (meth)acrylate are in the weight ratioof from 10:1 to about 1:10, and further, wherein the vinyl polymercontains from 80 to 20 weight percent lauryl (meth)acrylate.
 9. Anasphalt/asphaltene dispersant for petroleum, crude oil and hydrocarbonfractions thereof comprising a 1:1 mole ratio nonyl phenol-formaldehydeliquid resin having a molecular weight of from 2,000 to about 20,000 inoptional admixture with a vinyl polymer containing at least one of thehydrophilic vinylic monomers chosen from the group consisting of(meth)acrylamide, (meth)acrylic acid, (meth)acrylic acid ethoxylates,and (meth)acrylic propoxylates, or salts thereof; and at least onelipophilic vinylic monomer chosen from the group consisting of butyl(meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl(meth)acrylate, octyl (meth)acrylate, nonyl (meth)acrylate, decyl(meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, Oleyl(meth)acrylate, Linoleyl (meth)acrylate, myristyl (meth)acrylate, capryl(meth)acrylate, and mixtures thereof; and further wherein thehydrophilic vinylic monomer and lipophilic vinylic monomer are in theweight ratio of from 10:90 to about 90:10 and the vinylic polymer has amolecular weight of from about 10,000 to about 150,000.
 10. Thedispersant of claim 9 wherein the nonyl phenol-formaldehyde liquid resinand the vinylic polymer are admixed in a weight ratio between about80:20 to about 20:80; and further wherein the vinyl polymer containsfrom 20-90 weight percent lauryl (meth)acrylate and from 80-10 weightpercent hydroxyethyl (meth)acrylate.